moving files around

1 files changed, 0 insertions, 534 deletions

diff --git a/kernel/memory.c b/kernel/memory.c
deleted file mode 100644
index 62f3a38..0000000
--- a/kernel/memory.c
+++ /dev/null
@@ -1,534 +0,0 @@
-#include "memory.h"
-#include "kprint.h"
-#include "panic.h"
-
-#include <stdint.h>
-
-#include <kernel/entry.h>
-#include <kernel/memory/paging.h>
-
-/* kernel virtual space guarantees
- * 
- * the loader must set up the address space as follows
- * 1. kernel virtual space is 2GiB in size on 2GiB alignment.
- * 2. mappings begin at +0x7fc00000. this mapping space is sparse and its
- *    own mapping tables begin at +0x7fffe000.
- */
-
-#define kpm1_index(v) (((uint64_t)v >> pte_index_bits(1)) & 0x7ffff)
-#define kpm2_index(v) (((uint64_t)v >> pte_index_bits(2)) & 0x3ff)
-
-#define align_next(v, a) (((uint64_t)v + a - 1) & ~(a - 1))
-
-// a conservative 128MB for kernel heap
-#define KERNEL_HEAP_SPACE_SIZE (128 << 20)
-
-typedef int (*page_fault_handler_func)(uint32_t code, void *address);
-
-enum memory_space_flags
-{
-    SYSTEM_MEMORY_SPACE, // memory that cannot fault
-    ANONYMOUS_MEMORY_SPACE, // memory that can fault
-};
-
-struct memory_space
-{
-    enum memory_space_flags flags;
-    page_fault_handler_func handler;
-    void *base;
-    void *head;
-    struct memory_space *next;
-    struct memory_space *prev;
-};
-
-struct page
-{
-    uint32_t next: 31;
-    uint32_t used: 1;
-};
-
-extern char k_virt_base;
-extern char k_text_begin;
-extern char k_text_end;
-extern char k_data_begin;
-extern char k_data_end;
-
-static struct page *const page_array = (struct page *)0xffffffd800000000;
-static int first_free_page_index = -1;
-static size_t page_array_entries = 0;
-static size_t free_pages = 0;
-
-// the temporary mapping place. never use this permanently.
-static void *const temp = (void *)0xffffffffffa00000;
-static uint64_t *const kernel_pm1 = (uint64_t *)0xffffffffffc00000;
-static uint64_t *const kernel_pm2 = (uint64_t *)0xffffffffffffe000;
-
-static uint64_t *get_kernel_pm1e(void *vaddr);
-static uint64_t *get_kernel_pm2e(void *vaddr);
-static void *get_virtual_page(enum page_map_flags flags);
-static void *page_map_at(void *vaddr, phys_addr_t paddr, enum page_map_flags flags);
-
-// handlers for memory space types
-int anonymous_page_handler(uint32_t code, void *address);
-
-// the system memory_space's that are always present
-static struct memory_space kernel_image_space;
-static struct memory_space kernel_stack_space;
-static struct memory_space kernel_pagemap_space;
-// the kernel's own heap space
-static struct memory_space kernel_heap_space;
-
-// NULL if the system address spaces are not set up
-static struct memory_space *root_memory_space;
-
-static struct memory_range init_grab_pages(struct memory_range *ranges,
-                                           int count,
-                                           size_t size)
-{
-    struct memory_range request = {SYSTEM_MEMORY,
-                                   0,
-                                   align_next(size, PAGE_SIZE)};
-    
-    for (int i = 0; i < count; i++)
-    {
-        if (ranges[i].type != AVAILABLE_MEMORY ||
-            ranges[i].base < (1 << 20)) // leave pages below 1MiB alone.
-        {
-            continue;
-        }
-        else if (ranges[i].size > request.size)
-        {
-            request.base = ranges[i].base;
-            ranges[i].base += request.size;
-            ranges[i].size -= request.size;
-            return request;
-        }
-    }
-    
-    request.type = INVALID_MEMORY;
-    return request;
-}
-
-static size_t init_get_max_paddr(struct memory_range *ranges, int count)
-{
-    phys_addr_t max_paddr = 0;
-
-    // get the highest usable physical address in all memory ranges.
-    for (int i = 0; i < count; i++)
-    {
-        if (ranges[i].type != AVAILABLE_MEMORY)
-        {
-            continue;
-        }
-        
-        if ((ranges[i].base + ranges[i].size - 1) > max_paddr)
-        {
-            max_paddr = ranges[i].base + ranges[i].size - 1;
-        }
-    }
-    
-    return max_paddr;
-}
-
-static phys_addr_t get_kernel_pm4_phys(void)
-{
-    phys_addr_t pm4_phys;
-    __asm__ (
-             "mov %%cr3, %0\n\t"
-             : "=r"(pm4_phys)
-    );
-    
-    return page_address(pm4_phys, 1);
-}
-
-static phys_addr_t get_kernel_pm3_phys(void)
-{
-    phys_addr_t pm3_phys;
-    // make a temporary mapping to read pm4
-    uint64_t *pm4 = page_map_at(temp,
-                                get_kernel_pm4_phys(),
-                                CONTENT_RODATA|SIZE_2M);
-    
-    // pm3_phys is in pm4.
-    pm3_phys = page_address(pm4[pte_index(&k_virt_base, 4)], 1);
-    // never leave a temporary mapping
-    page_unmap(pm4);
-    
-    return pm3_phys;
-}
-
-static void init_map_page_array_pm2(struct memory_range *pm2_pages)
-{
-    // now we need to write the physical address of each pm2 page for the
-    // page_array in the kernel's pm3.
-    uint64_t *pm3 = page_map_at(temp,
-                                get_kernel_pm3_phys(),
-                                CONTENT_RWDATA|SIZE_2M);
-    
-    // the first index is NOT zero!
-    for (size_t i = 0; i < (pm2_pages->size / PAGE_SIZE); i++)
-    {
-        pm3[pte_index(page_array, 3) + i] = (pm2_pages->base + i *
-                                             PAGE_SIZE)|PAGE_NX|PAGE_WR|PAGE_PR;
-    }
-    // never forget to unmap temporary mappings.
-    page_unmap(pm3);
-}
-
-static void init_create_page_array_map(struct memory_range *pages,
-                                       struct memory_range *maps)
-{
-    // indices for page_array always start at 0
-    size_t entry_count = pages->size / PAGE_SIZE;
-    
-    // every 512 entries we need to re-map and clean.
-    for (size_t i = 0; i < entry_count; i += PAGE_TABLE_INDEX_MASK)
-    {
-        uint64_t *pm1 = page_map_at(temp,
-                                           maps->base + i * PAGE_SIZE,
-                                           CONTENT_RWDATA|SIZE_2M);
-        memset(pm1, 0, PAGE_SIZE);
-        for (size_t j = 0;
-             (j < PAGE_TABLE_INDEX_MASK) && ((j + i) < entry_count);
-             j++)
-        {
-            pm1[j] = (pages->base + (i + j) * PAGE_SIZE)|
-                     PAGE_NX|PAGE_WR|PAGE_PR; 
-        }
-        
-        page_unmap(pm1);
-    }
-}
-
-static void init_set_memory_range(struct memory_range *range)
-{
-    for (size_t i = 0; i < range->size / PAGE_SIZE; i++)
-    {
-        if (range->base / PAGE_SIZE + i > page_array_entries)
-        {
-            return;
-        }
-        
-        if (range->type == AVAILABLE_MEMORY)
-        {
-            page_free(range->base + PAGE_SIZE * i);
-        }
-        else
-        {
-            struct page *page = &page_array[range->base / PAGE_SIZE + i];
-            page->used = 1;
-        }
-    }
-}
-
-static void init_populate_page_array(struct memory_range *ranges, int count)
-{
-    for (int i = 0; i < count; i++)
-    {
-        init_set_memory_range(&ranges[i]);
-    }
-}
-
-static void init_create_page_array(struct memory_range *ranges, int count)
-{
-    // the highest actual physical memory address.
-    size_t max_paddr = init_get_max_paddr(ranges, count);
-    page_array_entries = max_paddr / page_size(1);
-    size_t page_array_size = page_array_entries * sizeof(struct page);
-    
-    // the physical pages that will contain page_array
-    struct memory_range pa_pages = init_grab_pages(ranges, count, page_array_size);
-    
-    // the number of page tables needed to map pa_pages
-    // this will be 1 on systems with less than 2GB of memory.
-    size_t pm1_count = page_count(pa_pages.size, 2);
-    struct memory_range pm1_pages = init_grab_pages(ranges,
-                                                    count,
-                                                    pm1_count * page_size(1));
-    
-    init_create_page_array_map(&pa_pages, &pm1_pages);
-    
-    // the number of page directories needed to map pa_pages
-    // this will be 1 on systems with less than 1TB of memory.
-    // who the fuck has 1TB of memory lol
-    size_t pm2_count = page_count(pa_pages.size, 3);
-    struct memory_range pm2_pages = init_grab_pages(ranges,
-                                                    count,
-                                                    pm2_count * page_size(1));
-    
-    init_create_page_array_map(&pm1_pages, &pm2_pages);
-    
-    // ok here goes
-    init_map_page_array_pm2(&pm2_pages);
-    
-    memset(page_array, 0, page_array_size);
-    
-    init_populate_page_array(ranges, count);
-    init_populate_page_array(&pa_pages, 1);
-    init_populate_page_array(&pm1_pages, 1);
-    init_populate_page_array(&pm2_pages, 1);
-}
-
-static struct memory_space init_system_space(void *base, void *head)
-{
-    struct memory_space space = {SYSTEM_MEMORY_SPACE, NULL, base, head, NULL, NULL};
-    return space;
-}
-
-static struct memory_space init_anonymous_space(void *base, void *head)
-{
-    struct memory_space space = {ANONYMOUS_MEMORY_SPACE,
-                                 &anonymous_page_handler,
-                                 base,
-                                 head,
-                                 NULL,
-                                 NULL};
-    
-    return space;
-}
-
-void memory_init(struct memory_range *ranges, int count)
-{
-    init_create_page_array(ranges, count);
-    // initialize always-present memory spaces for the vmm
-    kernel_image_space = init_system_space((void *)&k_text_begin,
-                                           (void *)align_next(&k_data_end, PAGE_SIZE));
-    kernel_stack_space = init_system_space((void *)KERNEL_ENTRY_STACK_BASE,
-                                           (void *)KERNEL_ENTRY_STACK_HEAD);
-    kernel_pagemap_space = init_system_space(kernel_pm1, (void *)-1LL);
-    
-    // initialize the kernel heap space
-    kernel_heap_space = init_anonymous_space(kernel_image_space.head,
-                                             (char *)kernel_image_space.head +
-                                             KERNEL_HEAP_SPACE_SIZE);
-    
-    // set up the list links
-    kernel_image_space.next = &kernel_heap_space;
-    kernel_heap_space.prev = &kernel_image_space;
-    kernel_heap_space.next = &kernel_stack_space;
-    kernel_stack_space.prev = &kernel_heap_space;
-    kernel_stack_space.next = &kernel_pagemap_space;
-    kernel_pagemap_space.prev = &kernel_stack_space;
-    
-    root_memory_space = &kernel_image_space;
-}
-
-static void *page_map_at(void *vaddr,
-                         phys_addr_t paddr,
-                         enum page_map_flags flags)
-{
-    uint64_t entry = PAGE_PR;
-    
-    switch (flags & CONTENT_MASK)
-    {
-        case CONTENT_RODATA:
-            entry |= PAGE_NX;
-            break;
-        case CONTENT_RWDATA:
-            entry |= PAGE_NX|PAGE_WR;
-            break;
-        default:
-            break;
-    }
-    
-    size_t offset;
-    uint64_t *pte;
-    
-    switch (flags & SIZE_MASK)
-    {
-        case SIZE_2M:
-            entry |= page_address(paddr, 2)|PAGE_LG;
-            offset = page_offset(paddr, 2);
-            pte = get_kernel_pm2e(vaddr);
-            break;
-        case SIZE_4K:
-            entry |= page_address(paddr, 1);
-            offset = page_offset(paddr, 1);
-            pte = get_kernel_pm1e(vaddr);
-            break;
-        default:
-            offset = 0;
-            pte = NULL;
-    }
-    
-    if (!pte)
-    {
-        return NULL;
-    }
-    
-    *pte = entry;
-    return (char *)vaddr + offset;
-}
-
-void *page_map(phys_addr_t paddr, enum page_map_flags flags)
-{
-    return page_map_at(get_virtual_page(flags), paddr, flags);
-}
-
-void page_unmap(void *vaddr)
-{
-    uint64_t *pte = get_kernel_pm2e(vaddr);
-    
-    if (pte && !(*pte & PAGE_LG))
-    {
-        pte = get_kernel_pm1e(vaddr);
-    }
-    
-    if (pte)
-    {
-        *pte = 0;
-    }
-    __asm__ ("invlpg (%0)" :: "r"(vaddr));
-}
-
-phys_addr_t page_alloc(void)
-{
-    int index = first_free_page_index;
-    
-    if (index > 0)
-    {
-        page_array[index].used = 1;
-        first_free_page_index = page_array[index].next;
-        free_pages--;
-    }
-    
-    return (phys_addr_t)index * page_size(1);
-}
-
-void page_free(phys_addr_t paddr)
-{
-    int index = paddr / page_size(1);
-    
-    if ((size_t)index > page_array_entries)
-    {
-        return;
-    }
-    
-    page_array[index].used = 0;
-    page_array[index].next = first_free_page_index;
-    first_free_page_index = index;
-    free_pages++;
-}
-
-void *heap_alloc(size_t size)
-{
-    (void)size;
-    return NULL;
-}
-
-void heap_free(void *block)
-{
-    (void)block;
-}
-
-void *memory_alloc(size_t size)
-{
-    (void)size;
-    return NULL;
-}
-
-void memory_free(void *block)
-{
-    (void)block;
-}
-
-static uint64_t *get_kernel_pm1e(void *vaddr)
-{
-    return &kernel_pm1[kpm1_index(vaddr)];
-}
-
-static uint64_t *get_kernel_pm2e(void *vaddr)
-{
-    return &kernel_pm2[kpm2_index(vaddr)];
-}
-
-static void *get_virtual_page(enum page_map_flags flags)
-{
-    (void)flags;
-    return NULL;
-}
-
-static struct memory_space *get_memory_space(void *address)
-{
-    // walk the memory space list
-    struct memory_space *space = root_memory_space;
-    
-    while (space)
-    {
-        if (space->base >= address && address <= space->head)
-        {
-            return space;
-        }
-        space = space->next;
-    }
-
-    return NULL;
-}
-
-int anonymous_page_handler(uint32_t code, void *address)
-{
-    if (code & PAGE_PR)
-    {
-        // there's no reason a protection violation should happen
-        // in anonymous space
-        panic(UNHANDLED_FAULT);
-    }
-    kputs("anonymous fault\n");
-    // kernel page mappings are built different
-    if (address >= (void *)&k_virt_base)
-    {
-        uint64_t *pm2e = get_kernel_pm2e(address);
-        
-        if (!page_address(*pm2e, 1))
-        {
-            // create a page table and install it
-            phys_addr_t pm1_phys = page_alloc();
-            if (pm1_phys)
-            {
-                uint64_t *pm1;
-                pm1 = page_map_at(temp, pm1_phys, CONTENT_RWDATA|SIZE_2M);
-                // zero the page
-                memset(pm1, 0, PAGE_SIZE);
-                // put the table where it goes
-                *pm2e = page_address(pm1_phys, 1)|PAGE_WR|PAGE_PR;
-                page_unmap(pm1);
-            }
-            else
-            {
-                panic(OUT_OF_MEMORY);
-            }
-        }
-        
-        uint64_t *pm1e = get_kernel_pm1e(address);
-        
-        if (pm1e)
-        {
-            phys_addr_t page_phys = page_alloc();
-            if (page_phys)
-            {
-                *pm1e = page_address(page_phys, 1)|PAGE_WR|PAGE_PR;
-                // clear a potentially dirty page.
-                memset((void *)page_address(address, 1), 0, page_size(1));
-            }
-        }
-    }
-    
-    return 0;
-}
-
-int page_fault_handler(uint32_t code, void *address)
-{
-    kputs("page faulmt\n");
-    struct memory_space *space = get_memory_space(address);
-    if (space && space->handler)
-    {
-        int result = space->handler(code, address);
-        
-        if (result)
-        {
-            panic(UNHANDLED_FAULT);
-        }
-    }
-    
-    return 0;
-}